1. Field of the Invention
The present invention relates to a three-dimensional shape measuring apparatus for measuring a three-dimensional shape.
2. Related Background Art
Three-dimensional shape measuring apparatus (hereinafter, sometimes referred to as three-dimensional measuring apparatus) provided with a contact type probe are most frequently used for measuring a three-dimensional shape. Such apparatus, however, need to keep the contact type probe contact an object to be measured under a certain force, and, therefore, they are not suitable for measurement of a soft object to be measured such as rubber.
Then three-dimensional measuring apparatus provided with an optical probe are used for such a case, whereby measurement can be done keeping the probe not contact the object to be measured. Further, there are three-dimensional measuring apparatus using a CCD camera to take images of the object to be measured at a plurality of angles and thereby measuring the shape by image processing.
The three-dimensional measuring apparatus provided with the contact type probe, however, had another problem, in addition to the above problem, that if the object to be measured had a smaller recess than the size of the distal end of probe, the probe was unable to be set in the recess, which disabled the measurement.
Even in the case of measurement with the three-dimensional measuring apparatus provided with the optical probe, the object to be measured needs to have a space through which a beam emitted from the probe and reflected light thereof can pass. Thus, the three-dimensional measuring apparatus provided with the optical probe had a problem that they were not able to measure well an object to be measured having a shape of narrow and deep channel.
The three-dimensional measuring apparatus measuring the shape by image processing had a problem that shadow portions were unable to be measured even if the object to be measured was photographed in a plurality of directions by the CCD camera.